#include <iostream>
#include <unistd.h>

using namespace std;

int main()
{
    putenv("hello=you can see me");
    cout << "begin..." << endl;
    char* const myargv[] = {
        "env",
        NULL
    };
    execvpe("env", myargv,environ);
    // execl("/bin/ls","-a","-l",NULL);
    cout << "end..." << endl;
    return 0;
}


// int main()
// {
//     putenv("hello=you can see me");
//     cout << getenv("hello") << endl;
//     cout << "begin..." << endl;
//     execlp("pwd", "pwd", NULL);
//     // execl("/bin/ls","-a","-l",NULL);
//     cout << "end..." << endl;
//     return 0;
// }
